Multipurpose powerhead

ABSTRACT

A multipurpose powerhead having a barrel member internally shaped with a chamber for receiving a cartridge is coupled to an axially aligned body member. A firing pin member projects above the surface of the body member and reaches into the cartridge chamber. A cylindrically shaped mass having an axial bore is slidably carried on the body member and a helical biasing spring urges the mass toward the firing pin member. When the powerhead is deployed by a rapidly accelerating surgical-rubber-tubing speargun, the inertial drag of the cylindrical mass overcomes the biasing force of the biasing spring. A resiliently mounted spur secured to the cylindrical mass overrides and engages a retaining rim to cock the powerhead during the deployment stage. When the muzzle of the barrel member impacts against a target, such as a large fish, the powerhead is arrested from further travel. Meanwhile, the forward momentum of the cylindrical mass pulls the resiliently mounted spur from its engaged position on the annular retaining rim. This forward momentum is augmented by the biasing force of the biasing spring which accelerates the cylindrical mass toward the firing pin member at an increasing velocity. The combined force attributed to the forward momentum and the biasing force is sufficient to detonate the cartridge when the cylindrical mass strikes the firing pin. Having all the moving parts exposed to the ambient water prevents the collection of impurities and the consequent jamming of the powerhead.

ilnited States Patent [191 Prodanovich [4 Oct. 1,1974

[ MULTIPURPOSE POWERHEAD [76] Inventor: Jack Prodanovich, 3334 Sterne, San

Diego, Calif. 92106 [22] Filed: Aug. 1, 1973 [21] Appl. No.: 384,553

Primary Examiner-Benjamin A. Borchelt Assistant ExaminerC. T. Jordan Attorney, Agent, or FirmRichard S. Sciascia; Ervin F. Johnston; Thomas Glenn Keough [5 7] ABSTRACT A multipurpose powerhead having a barrel member internally shaped with a chamber for receiving a cartridge is coupled to an axially aligned body member. A firing pin member projects above the surface of the body member and reaches into the cartridge chamber. A cylindrically shaped mass having an axial bore is slidably carried on the body member and a helical biasing spring urges the mass toward the firing pin member. When the powerhead is deployed by a rapidly accelerating surgical-rubber-tubing speargun, the inertial drag of the cylindrical mass overcomes the biasing force of the biasing spring. A resiliently mounted spur secured to the cylindrical mass overrides and engages a retaining rim to cock the powerhead during the deployment stage. When the muzzle of the barrel member impacts against a target, such as a large fish, the powerhead is arrested from further travel. Meanwhile, the forward momentum of the cylindrical mass pulls the resiliently mounted spur from its engaged position on the annular retaining rim. This forward momentum is augmented by the biasing force of the biasing spring which accelerates the cylindrical mass toward the firing pin member at an increasing velocity. The combined force attributed to the forward momentum and the biasing force is sufficient to detonate the cartridge when the cylindrical mass strikes the firing pin. Having all the moving parts exposed to the ambient water prevents the collection of impurities and the consequent jamming of the powerhead.

6 Claims, 4 Drawing Figures PMENIED N974 FUT- MULTIPURPOSE POWERHEAD STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Underwater spear guns for the taking of game fish or for protection from marine predators have relied on surgical rubber tubings, springs, compressed gas, etc. to launch shafts carrying sharpened darts. Capturing large undersea creatures having tough scales or skins becomes more difficult since the darts are unable to penetrate effectively or bounce off harmlessly. By necessity, an auxiliary device of some sort is needed for penetration. One well known device which either blows a dart deep within a creatures body or incapacitates it outright, is the powerhead.

Powerheads are many and varied in design. Usually they employ a dead firing pin against which the primer of a cartridge is driven to effect detonation. An inherent deficiency of this design resides in the fact that there must be a considerable inpacting force between the powerhead and the fish to achieve a detonation. Needless to say, there is a tendency for most dead firing pin powerheads to fail when deployed at long range due to the water drag acting upon all underwater missiles. Because of the limitations of the dead firing pin type powerheads, spring-cocked mechanisms have been designed which are actuated upon light contact. However, most of these spring-cocked powerheads are highly dangerous, since a cocked mechanism always is vulnerable to accidental triggering, particularly so in a marine environment where a diver is subjected to wave action, turbulence and strong currents. One noteworthy attempt to remedy the defects of both the dead firing pin and the precocked powerheads is shown in the U.S. Pat. No. 2,819,674 issued Jan. 14, 1958 to the present inventor, Jack Prodanovich. This patented device internally carries a heavy cylinder terminating in a firing pin. The cylinder is latched in place and, during deployment, a spring is compressed by the cylinder to cock the powerhead en route to the target. Only a relatively light impact on a trigger mechanism allows release of the spring to force the heavy cylindrical body forward to detonate the cartridge. While the patented device operated in a highly satisfactory manner in a wide variety of situations, it was discovered that under conditions where sand, grit, or other impurities could work into the internal mechanism of the device, malfunction could occur. Thus, there is a continuing need to provide a powerhead device which detonates at long ranges, which reduces the hazard to a diver, and which functions reliably under adverse conditions.

SUMMARY OF THE INVENTION The invention is directed to providing a powerhead adapted for accelerated remote deployment to detonate a cartridge upon impact. A barrel member is internally shaped to receive a cartridge and an elongate body member is coupled to it. At one end the body member is shaped with a longitudinal groove on its outer surface and a firing pin is disposed in this groove to contact the cartridge. At the opposite end of the body member an annular rim is mounted to outwardly project from the body members surface. A cylindrically-shaped mass is provided with a bore sized to receive and to allow axial displacement on the outer surface of the body member. When the mass is at the one end of the body member it will strike the firing pin and a spur carried on the mass is aligned to engage the annular rim when the mass is at the opposite end of the body member. A biasing spring tends to hold the mass against the firing pin, yet upon a rapidly accelerated deployment of the powerhead, the inertial drag of the mass is sufficient to overcome the biasing force of the biasing spring and the spur latches onto the annular rim. Upon impact, the momentum of the mass is sufficient to pull the spur from its latched engagement on the annular rim and the additive force attributed to the mass momentum and the biasing force is sufficient to detonate the cartridge when the firing pin member is struck by the mass.

It is a prime object of the invention to provide a more reliable powerhead.

Another object of the invention is to provide a powerhead which will detonate a cartridge at long range.

Still another object is to provide a powerhead reducing the hazard to a diver.

Yet another object is to provide a powerhead which is freely washable and of reduced vulnerability to the effects of sand, grit or other impurities.

Another object is to provide a powerhead having an interchangeable dart capability.

A further object is to provide a powerhead which has a variable impact-sensitivity to initiate detonation.

Still another object is to provide a powerhead which is cocked only upon a rapidly accelerated deployment toward a target.

These and other objects of the invention will become more readily apparent from the ensuing description when taken with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view in cross section of the powerhead in the ready stage.

FIG. 2 is a side view of the invention during the deployment stage.

FIG. 3 shows the powerhead during the impact stage.

FIG. 4 is a side view partially in cross section showing the invention during the detonation stage.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. 1 depicts a preferred embodiment of the powerhead 10 in the standby stage. With the elements to be described below, arranged as shown, there is minimal risk to a diver from inadvertent actuation of the powerhead as he performs The exact configuration of the dart is not critical to the functioning of this invention. although it is recognized that one configuration possesses superior characteristics for a particular job while other designs work better under other conditions. Optionally. the dart is dispensed with entirely and the expanding gases and projectile from the cartridge are sufficient to immobilize smaller marine creatures. Let it suffice to say that if a dart is to be employed, its outer tip is appropriately shaped to achieve the desired degree of penetration.

At the outwardmost end of the barrel member an outwardly flaring muzzle 11a is disposed to ensure that the barrel member will not itself penetrate the targets body. The functional cooperation of other elements to be described depend on there being a sharp impact when the powerhead strikes.

A pair of slots 11b are provided inwardly of the muzzle of the barrel member to allow for the passage of a retrieval line strung through an appropriately disposed hole in the dart. The slots secondarily function to vent excessive amounts of gas created by the detonation of a cartridge. At the opposite end of the barrel member an internally threaded section 110 is machined to engage correspondingly disposed threads on one end of a body member 15.

Body member 15 is fashioned from a rod-shaped piece of stock and is provided with a firing pin groove 16 which serves to contain a firing pin member 17. The firing pin member is sized to slide freely within the groove and is formed with a projection portion 17a jutting above the surface of the body member while a stem portion 17b lies in the groove. The stem portion is sufficiently dimensioned to reach inwardly in barrel member 11 to rest on the cartridge chambered in chamber 12.

A collar member 18 is carried adjacent the inner end of the barrel. member and preferably is internally threaded to mate with the threads formed on body member 15. Extensive testing and operation have demonstrated that it is desirable to limit the longitudinal travel of stem portion 17b and also to retain the firing pin member in firing pin groove 16. Were the firing pin member free to longitudinally travel unrestricted in the groove, possible damage to the stem portion of the firing pin member could result from over-travel during detonation of the cartridge. Thus, with the collar member in place, the projection portion of the firing pin member abuts the collar member to ensure the proper spacing of the stem member to achieve reliable detonation. In addition, the collar serves to retain the firing pin member in the groove, particularly during reloadmg.

A cylindrically-shaped mass 19 having an axial bore 19a is carried on the outer surface of body member 15. The dimensions of the axial bore are slightly larger than the diameter of the body member to permit rotary as well as reciprocal motion on the body member. On the outer surface of the cylindrically-shaped mass, a resilient arm 20 is secured by a pair of screws 20a and a spur element 21 is mounted on the arms outer end. The spur element is provided with dependent spur portion 21a which reaches into the same axial projection of an annular rim 22.

The annular rim radially projects from an integrally coupled tubular element 23. An inner bore 23a of the tubular element is threaded to allow the coupling of the annular rim and tubular element on a correspondingly threaded portion on the outer surface of body member 15. The threaded inner bore 23a also serves to facilitate the interconnection of the powerhead to a spear gun shaft 24 which gives the powerhead a long range deployment capability.

As mentioned above. the dimensions of the annular rim are such as to permit the override of spur portion 21 when mass 19 approaches the annular rim. The forward slope of the annular rim cams the spur portion outwardly until it overrides the rim. Then the biasing action of resilient arm 20 snaps the spur portion inwardly to securely latch it in-place. see FIG. 2. The shoulder of the annular rim is slightly rounded to expedite the latching operation as well as serving to facilitate the release of the mass when the powerheads forward momentum has been rapidly arrested during impact. Providing different contours 22a and 2217 on different portions of the rims shoulder decreases or increases the powerheads sensitivity to impact. To elaborate, the sharper shoulder contour 22a requires a sharper impact to dislodge or disengage the latched spur portion. Thus, for long range use it may be better to have mass 19 rotated to align spur portion 21a with the more rounded shoulder contour 22b since the impact would be less. With respect to the present invention the force of impact created when the powerhead is dropped 12 inches in air was sufficient to unlatch the spur portion and to ensure detonation of the cartridge.

A helical biasing spring 25 is interposed between the annular rim and the cylindrically shaped mass and holds the mass against projection portion 17a of the firing pin member. With the mass held in this position the powerhead is at the ready stage and is quite safe, see FIG. 1. Accidently bumping muzzle 11a will not prematurely detonate the cartridge since the weight of the mass resting on the projection portion 17a is insuffl cient to effect detonation. The spring constant of biasing spring 25 is predetermined to ensure that upon the deployment of the powerhead at a target, the inertial drag of cylindrically shaped mass 19 is sufficient to overcome the biasing force of the biasing spring 25 to allow the aforedescribed latching of spur portion 21a on annular rim 22. A conventional spear gun using rubber surgical tubing exerting a tensile force of pounds, successfully provided a sufficient acceleration. With this acceleration, the inertial drag of a cylindrically-shaped mass 19 weighing less than one-half pound overcame the few pounds biasing force of helical biasing spring 25 and latched the spur portion in place. This arrangement gave the powerhead more than a critical impact velocity, within a 12 foot range, to unlatch spur portion 21a upon impact.

In operation, cylindrically-shaped mass 19 functions as a means inertially reacting to remain in its preestablished condition while other elements of the powerhead are being accelerated or deccelerated. Noting FIG. 2, the powerhead is depicted during launch or deployment stage. Arrows 26 indicate the rapid acceleration of all elements in the powerhead except for cylindrically-shaped mass 19. The cylindrically-shaped mass tends to remain at rest and by so staying in its state of rest shoulder contour 22a of annular rim 22 is overridden by spur portion 21a of spur element 21 to latch the mass in the cocked position.

Turning now to FIG. 3 the inertial reaction of mass 19 during the impact stage is schematically demonstrated. Muzzle 11a forcefully strikes a target 27 such as a large fish and is arrested from further travel. Because of the breadth of the muzzle, the powerhead and spear shaft immediately stop. However, the inertial reaction of cylindrically-shaped mass 19 is to continue forward toward the target. The momentum of the mass pulls spur portion 21a of the spur element from its engaged position on annular rim 22 and the mass continues to move toward firing pin member 17. Simultaneously, the compressed biasing spring 25 exerts a biasing force which accelerates the mass toward the firing pin member.

The detonation stage is depicted in FIG. 4 as cylindrically-shaped mass 19 contacts projection portion 17a of the firing pin member and the detonation of the cartridge occurs. A combined force attributed to the momentum of the mass and the biasing force of the biasing spring additively transfer enough striking force to the firing pin member to ensure that stem portion 17b detonates the cartridge.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings, and, it is therefore understood that within the scope of the disclosed invention concept, the invention may be practiced otherwise than specifically described.

What is claimed is:

1. A powerhead adapted for accelerated remote deployment to detonate a cartridge upon impact comprismg:

a barrel member internally shaped to receive said cartridge;

an elongate body member axially aligned with and coupled to said barrel member, at one end said body member is provided with a longitudinal groove on its outer surface;

a firing pin member disposed in said groove formed to make contact with said cartridge;

means mounted on the opposite end of said body member for radially projecting therefrom;

means for inertially reacting to said deployment and said impact being provided with a bore sized to receive and allow axial displacement on the outer surface of said body member to permit the striking of said firing pin member when at said one end and further provided with a spur aligned to engage the radially projecting means when at said opposite end; and

means carried on said body member for biasing the inertially reacting means toward said firing pin member. the biasing means has a spring constant insufficient to overcome the inertial drag of said inertially reacting means when deployment occurs yet said spring constant is of sufficient magnitude to detonate said cartridge when coacting with the momentum of said inertially reacting means when impact occurs. upon said deployment, the inertial drag of said inertially reacting means is sufficient to overcome the biasing force of the biasing means and said spur engages said radially projecting means and upon said impact the momentumof said inertially reacting means is sufficient to pull said spur from said radially projecting means and the additive force attributed to said momentum and said biasing force is sufficient to detonate said cartridge when said firing pin member is struck.

2. A powerhead according to claim 1 in which the body member is cylindrically shaped, said inertially reacting means has an annular cross-sectional configuration and said biasing means is a helical spring wrapped about said body member and interposed between said inertially reacting means and said radially projecting means, said body member, said inertially reacting means, and said biasing means are exposed to their surroundings to prevent the settling and accumulation of function-impairing particles.

3. A powerhead according to claim 2 further including a collar member fitted about said body member to retain said firing pin member in said groove and to limit the longitudinal travel of said firing pin member in said groove.

4. A powerhead according to claim 3 in which said inertially reacting means further includes a resilient arm coupled to said spur allowing it to be deflected outwardly when engaging said radially projecting means and said radially projecting means has an annular rim shaped configuration.

5. A powerhead according to claim 4 in which said barrel member is further shaped to retain a dart which is expelled upon detonation of said cartridge and said radially projecting means has a cylindrical portion for connection to a spear gun shaft.

6. A powerhead according to claim 5 in which the shoulder contour of the annularly-rim-shaped, radially projecting means is differently configured on adjacent surface areas to give said powerhead a variable sensitivity upon deployment and impact. 

1. A powerhead adapted for accelerated remote deployment to detonate a cartridge upon impact comprising: a barrel member internally shaped to receive said cartridge; an elongate body member axially aligned with and coupled to said barrel member, at one end said body member is provided with a longitudinal groove on its outer surface; a firing pin member disposed in said groove formed to make contact with said cartridge; means mounted on the opposite end of said body member for radially projecting therefrom; means for inertially reacting to said deployment and said impact being provided with a bore sized to receive and allow axial displacement on the outer surface of said body member to permit the striking of said firing pin member when at said one end and further provided with a spur aligned to engage the radially projecting means when at said opposite end; and means carried on said body member for biasing the inertially reacting means toward said firing pin member, the biasing means has a spring constant insufficient to overcome the inertial drag of said inertially reacting means when deployment occurs yet said spring constant is of sufficient magnitude to detonate said cartridge when coacting with the momentum of said inertially reacting means when impact occurs, upon said deployment, the inertial drag of said inertially reacting means is sufficient to overcome the biasing force of the biasing means and said spur engages said radially projecting means and upon said impact the momentum of said inertially reacting means is sufficient to pull said spur from said radially projecting means and the additive force attributed to said momentum and said biasing force is sufficient to detonate said cartridge when said firing pin member is struck.
 2. A powerhead according to claim 1 in which the body member is cylindrically shaped, said inertially reacting means has an annular cross-sectional configuration and said biasing means is a helical spring wrapped about said body member and interposed between said inertially reacting means and said radially projecting means, said body member, said inertially reacting means, and said biasing means are exposed to their surroundings to prevent the settling and accumulation of function-impairing particles.
 3. A powerhead according to claim 2 further including a collar member fitted about said body member to retain said firing pin member in said groove and to limit the longitudinal travel of said firing pin member in said groove.
 4. A powerhead according to claim 3 in which said inertially reacting means further includes a resilient arm coupled to said spur allowing it to be deflected outwardly when engaging said radially projecting means and said radially projecting means has an annular rim shaped configuration.
 5. A powerhead according to claim 4 in which said barrel member is further shaped to retain a dart which is expelled upon detonation of said cartridge and said radially projecting means has a cylindrical portion for connection to a spear gun shaft.
 6. A powerhead according to claim 5 in which the shoulder contour of the annularly-rim-shaped, radially projecting means is differently configured on adjacent surface areas to give said poweRhead a variable sensitivity upon deployment and impact. 